Multiple electrode liquid heater



Dec, 25, 1934. c oss 1,985,623

MULTIPLE ELECTRODE LIQUID HEATER Filed Feb. 27, 1933 INVENTOR,

44., A TTORNE y Patented Dec. 25, 1934 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to new and useful improvements in multiple electrode liquid heaters.

It is one of the principal objects of my inven tion to provide a liquid heater in the form of a common double boiler, in which multiple electrodes may be connected in different combinations to obtain various rates of heating. These electrodes may be equally or unequally spaced. To get the greatest amount of heat at the bottom of the heater, where it is most needed to insure proper convection, the intermediate and lower electrodes may be placed closer together than the intermediate and top electrodes.

As an effective aid to simplicity of construction and economy of manufacture, the electrodes in my liquid heater may take the form of bands. If, for example, three equally spaced bands are employed, one near the bottom, one at the top, and one centrally placed between them, they can be connected in combinations to give high, intermediate and low heats.

When the outside bands are connected to one side of a circuit and the center band is connected to the other side, we get the shortest distance between the electrodes, whereupon there is the largest flow of current and the highest heat. II the upper band is now disconnected, the current will flow from the center band to the lower band to give an intermediate heat. Then, if the connection is shifted from the middle band to the top band, the current will flow direct to the latter from the lower band to produce a iow heat, since the path of flow and the resistance are each twice as great as they were for the second combination.

In a double boiler employing my multiple electrode invention, the high heat may be used for heating the inner vessel at the start, and the lower heat for keeping it simmering after it is hot.

An important object of my invention is the ability to place the heat where it is wanted. In other words, the multiple electrodes can be so spaced or connected as to definitely locate and maintain the heat for proper cooking effects. Where gravity is depended upon to circulate the water, it is easy to locate the greatest heat at the bottom of the double boiler through the place ment of two slightly spaced electrodes there.

Other important and incidental objects will be brought out in the following specification and particularly set forth in the subjoined claims.

In the accompanying drawing illustrating one form of embodiment of my invention, Figure 1 is a side elevational view of a double boiler embody-- ing the multiple electrodes in the form of bands,

together with the detachable plug and cord unit for conducting electric current to combinations thereof. Figure 2 is a perspective view of the outer container, showing three band electrodes therein. And Figure 3 is a sectional view taken 5 through the double boiler on the line 33 of Figure 1.

Referring to the accompanying drawing for a detailed description of the form of embodiment of my invention illustrated therein, the numeral 1 l0 designates the outer container and 2 the inner receptacle of a heating vessel of the double boiler type. The vessels themselves may be made of an electrically insulating material such as china, glass or phenolic condensation products, or ma- 15 terial such as enameled iron having an insulating coating. It should be noted at this point, however, that while I have illustrated my invention as applied to a double boiler, it may be embodied in any other type of cooking or heating vessel in which a liquid is electrically heated.

Although various kinds of electrodes may be employed, I prefer to use those of the band type for achieving the objects of my invention. Accordingly, I attach to the inner portion of the 25 curved wall of the outer receptacle or vessel 1, three equally spaced, curved band electrodes, an upper band 3, an intermediate band 4 and a lower band 5.

The bands 3, 4 and 5, which preferably decrease in length from the top down, are secured to the curved wall of the outer container 1 by conducting elements such as screws 6, '7 and 8 respectively. Each screw, which passes through a hole in the middle part of its respective electrode, is insulated from the vessel wall by washers 9 and 10 constructed of suitable insulating material. Beyond the washers 10, nuts 11 are applied to the screws to co-operate with the screw heads in holding the band electrodes tightly against the insulating washers 9 which engage the wall of the container.

The outer container 1 is preferably filled with a conducting liquid such as salt water to a level which is above the upper band electrode 3 when the heater is in operation. An inner receptacle 2 may be placed within the outer vessel 1 by its handle 12, the outer vessel also having a handle 13 by which it may be carried from place to place.

In order to connect the band electrodes 3, 4, and 5 in desired combinations to obtain diiferent rates of heat from the liquid within the outer vessel 1, I provide a plug and cord unit 14 for conducting current to them from a source of electric current supply (not shown). From a main trunk 15, two cords 16 and 17 emerge, one for each side of the circuit. The cord 17 terminates in two branches 18 and 19, with insulated plugs 20 and 21 attached to their outer ends. A similar plug 22 is secured to the free end of the cord 16. These plugs are adapted to interchangedly fit the outer ends of the conducting screws 6, '7 and 8.

When it is desired to obtain a high heat within the outer vessel 1, particularly for heating the inner receptacle 2 at the start, the plugs 20 and 21 are applied to the upper and lower screws 6 and 8 to connect them to one side of the circuit, and the plug 22 is applied to the center screw 7 to connect it to the other side of the circuit. This combination gives the shortest distance or path through the liquid between the electrodes 3, 4 and to provide the highest or maximum heat, the flow of current being from the center band to each of the outside bands.

If the upper plug 20 is now disconnected, the current will flow from the center band 4 to the lower band 5 to give an intermediate heat. Then if the middle plug 22 is shifted from the center screw '7 to the top screw 6, the current will flow from the lower band 5 to the upper band 3, twice the distance as before, and with the liquid offering twice the resistance, to give a low heat. The latter may be used to keep the inner receptacle simmering after it is hot.

It is thus seen that I can secure and maintain difierent rates of heat, by connecting different combinations of the electrodes in the electric circuit through the detachable plugs. It is possible to induce the current flow from the center to the outside electrodes to obtain a high degree of heat or to eliminate one of them to obtain lower rates of heating.

I do not wish to be limited to the details of construction and arrangement herein shown and described, and any changes or alterations may be made therein within the scope of the subjoined claims.

Having described my invention, I claim:

1. In a heater of the type described, a liquid container, three or more spaced horizontal electrodes adapted to be covered by the liquid in said container, contact members for said electrodes projecting through .a side wall of said container, an electric circuit, and plugs connected to said circuit for application to two or more of said contact members to include their respective electrodes in said circuit.

2. In a heater of the type described, a liquid container, an upper, a lower and an intermediate electrode in said container, the latter containing a conducting liquid covering said electrodes, an electric circuit, conducting members projecting from said electrodes through a side wall or said container, and a unit comprising three plugs, two of said plugs being connected to one side of said circuit and the other plug being connected to the other side of said circuit, the plugs connected to one side of said circuit adapted to be applied to the outside conducting members and the plug connected to the other side of said circuit adapted to be applied to the middle conducting member to obtain a high heatingrate of the liquid within said container, one of the first two plugs adapted to be disconnected and the other two applied to said connecting members to obtain an intermediate and a lower rate of heating the liquidwithin the container.

3. In a heater of the type described, a liquid container, an upper, a lower and an intermediate band electrode in said container, the latter containing a conducting liquid covering said electrodes, an electric circuit, conducting members passing through said bands and a side wall of container to secure said bands to the inner surface of said wall, and a unit comprising three plugs, two of said plugs being connected to one side of said circuit and the other plug being connected to the other side of said circuit, the plugs connected to one side of said circuit adapted to be applied to the outside conducting members and the plug connected to the other side of said circuit adapted to be applied to the middle conducting member to obtain a high heating rate of the liquid within said container, one of the first two plugs adapted to be disconnected and the other two applied to said connecting members to obtain an intermediate and a lower rate of heating the liquid within the container.

a. In a heater or" the type described, a liquid container, three or more electrodes in said container, the latter containing a conducting liquid covering said electrodes, an electric circuit, conducting members projecting from said electrodes, through a side wall of the container, and connected plug means for connecting said conducting members in different combinations of two or more in said circuit to obtain various rates of heating.

5. In a heater of the type described, a liquid container, a series of band electrodes in said container, the latter containing a conducting fluid covering said electrodes, an electric circuit, conducting members passing through said bands and a side wall of said container, and connected plug means for connecting said conducting members in difierent combinations of two or more in said circuit to obtain various rates of heating.

CARROLL A. ROSS. 

